From (REF ), it looks appropriate to assume for the potential \(U(u)\)  in the starting constant-mass Schrödinger equation (REF ) some function of the real exponential \(e^u\) . Let us consider the Morse potential [1]}, which may be written as [2]}
\(U(u) = B^2 e^{-2u} - B(2A+1) e^{-u}, \qquad -\infty < u < + \infty , \) 
